1. Field of the Invention
The present invention concerns a high-frequency amplifier arrangement comprising an input coupling circuit which has at least a first and a second access to couple a first and a second system, at least one of which is an amplifier.
Such amplifier arrangements according to the invention are particularly used for base transceiver stations of a mobile radio network. Such a network is, in effect, formed by various base transceiver stations covering each a defined geographical area and transmitting over various frequency channels which are very close together. In order to avoid interference among areas, the output power of each base transceiver station is to be strictly limited to the coverage area.
2. Description of the Related Art
A high-frequency amplifier is specifically known from French Patent Specification no. 1452462. However, no output power controller is provided.
For making the output power of the amplifiers vary, PIN-diode attenuators are known to be used. However, when the diodes used in such attenuators are to be capable of carrying high power levels, higher than 10 mW for example, they become very costly.